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Security Bulletin: This Power System update is being released to address CVE-2026-43198

Security Bulletin


Summary

The Linux kernel is used by the Virtualization Management Interface in PowerVM to support network communication with the Hardware Management Console. This bulletin provides a remediation for the impacted vulnerability, CVE-2026-43198, by upgrading PowerVM and thus addressing the exposure to the kernel vulnerability.

Vulnerability Details

CVEID:   CVE-2026-43198
DESCRIPTION:   In the Linux kernel, the following vulnerability has been resolved: tcp: fix potential race in tcp_v6_syn_recv_sock() Code in tcp_v6_syn_recv_sock() after the call to tcp_v4_syn_recv_sock() is done too late. After tcp_v4_syn_recv_sock(), the child socket is already visible from TCP ehash table and other cpus might use it. Since newinet-pinet6 is still pointing to the listener ipv6_pinfo bad things can happen as syzbot found. Move the problematic code in tcp_v6_mapped_child_init() and call this new helper from tcp_v4_syn_recv_sock() before the ehash insertion. This allows the removal of one tcp_sync_mss(), since tcp_v4_syn_recv_sock() will call it with the correct context.
CWE:   CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
CVSS Source:   Linux
CVSS Base score:   9.8
CVSS Vector:   (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)

Affected Products and Versions

Affected Product(s)Version(s)
Virtualization Management InterfaceFW1110.00 - FW1110.31
Virtualization Management InterfaceFW1120.00 - FW1120.01
Virtualization Management InterfaceFW1060.00 - FW1060.81

For Power10 servers, a mitigation is being released only for FW1060 but all prior firmware releases on the listed products are vulnerable.

Remediation/Fixes

IBM strongly recommends customers with the products below install FW1110.32(1110_160), FW1120.02(1120_195), or newer to remediate this vulnerability as soon as possible.

Power 11
1) IBM Power System S1122 (9824-22A)
2) IBM Power System S1124 (9824-42A)
3) IBM Power System S1122s (9824-22B)
4) IBM Power System S1114 (9824-41B)
5) IBM Power System L1122 (9856-22H)
6) IBM Power System L1124 (9856-42H)
7) IBM Power System E1150 (9043-MRU)
8) IBM Power System S1112 (9242-21B, 9242-21T)

The images mentioned above can be located at IBM Fix Central : https://www.ibm.com/support/fixcentral/

 

IBM strongly recommends customers with the products below install FW1060.82(1060_199) or newer to remediate this vulnerability as soon as possible.

Power 10
1) IBM Power System S1022 (9105-22A)
2) IBM Power System S1024 (9105-42A)
3) IBM Power System S1022s (9105-22B)
4) IBM Power System S1014 (9105-41B)
5) IBM Power System L1022 (9786-22H)
6) IBM Power System L1024 (9786-42H)
7) IBM Power System E1050 (9043-MRX)
8) IBM Power System S1012 (9028-21B)

The images mentioned above can be located at IBM Fix Central : https://www.ibm.com/support/fixcentral/

 

Workarounds and Mitigations

None

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References

Complete CVSS v3 Guide
On-line Calculator v3

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Related Information

IBM Secure Engineering Web Portal
IBM Product Security Incident Response Blog

Acknowledgement

Change History

23 Sep 2026: Initial Publication

*The CVSS Environment Score is customer environment specific and will ultimately impact the Overall CVSS Score. Customers can evaluate the impact of this vulnerability in their environments by accessing the links in the Reference section of this Security Bulletin.

Disclaimer

According to the Forum of Incident Response and Security Teams (FIRST), the Common Vulnerability Scoring System (CVSS) is an "industry open standard designed to convey vulnerability severity and help to determine urgency and priority of response." IBM PROVIDES THE CVSS SCORES ""AS IS"" WITHOUT WARRANTY OF ANY KIND, INCLUDING THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. CUSTOMERS ARE RESPONSIBLE FOR ASSESSING THE IMPACT OF ANY ACTUAL OR POTENTIAL SECURITY VULNERABILITY. In addition to other efforts to address potential vulnerabilities, IBM periodically updates the record of components contained in our product offerings. As part of that effort, if IBM identifies previously unidentified packages in a product/service inventory, we address relevant vulnerabilities regardless of CVE date. Inclusion of an older CVEID does not demonstrate that the referenced product has been used by IBM since that date, nor that IBM was aware of a vulnerability as of that date. We are making clients aware of relevant vulnerabilities as we become aware of them. "Affected Products and Versions" referenced in IBM Security Bulletins are intended to be only products and versions that are supported by IBM and have not passed their end-of-support or warranty date. Thus, failure to reference unsupported or extended-support products and versions in this Security Bulletin does not constitute a determination by IBM that they are unaffected by the vulnerability. Reference to one or more unsupported versions in this Security Bulletin shall not create an obligation for IBM to provide fixes for any unsupported or extended-support products or versions.

Document Location

Worldwide

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Document Information

Modified date:
23 September 2026

Initial Publish date:
23 September 2026

UID

ibm17288530

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